Intrinsic dopamine and acetylcholine dynamics in the striatum of mice.

External rewards such as food and money are potent modifiers of behaviour1,2. Pioneering studies established that these salient sensory stimuli briefly interrupt the tonic discharge of neurons that produce the neuromodulators dopamine (DA) and acetylcholine (ACh): midbrain DA neurons (DANs) fire a burst of action potentials that broadly elevates DA in the striatum3,4 at the same time that striatal cholinergic interneurons (CINs) produce a characteristic pause in firing5,6. These phasic responses are thought to create unique, temporally limited conditions that motivate action and promote learning7-11. However, the dynamics of DA and ACh outside explicitly rewarded situations remain poorly understood. Here we show that extracellular DA and ACh levels fluctuate spontaneously and periodically at a frequency of approximately 2 Hz in the dorsal striatum of mice and maintain the same temporal relationship relative to one another as that evoked by reward. We show that this neuromodulatory coordination does not arise from direct interactions between DA and ACh within the striatum. Instead, we provide evidence that periodic fluctuations in striatal DA are inherited from midbrain DANs, while striatal ACh transients are driven by glutamatergic inputs, which act to locally synchronize the spiking of CINs. Together, our findings show that striatal neuromodulatory dynamics are autonomously organized by distributed extra-striatal afferents. The dominance of intrinsic rhythms in DA and ACh offers new insights for explaining how reward-associated neural dynamics emerge and how the brain motivates action and promotes learning from within.

Effect of a 1-year physical activity intervention on quality of life, fatigue, and distress in adult childhood cancer survivors-A randomized controlled trial (SURfit).

INTRODUCTION: Childhood cancer survivors (CCS) are at risk of experiencing lower quality-of-life, fatigue, and depression. Few randomized controlled trials have studied the effect of physical activity (PA) on these in adult long-term CCS. This study investigated the effect of a 1-year individualized PA intervention on health-related quality-of-life (HRQOL), fatigue, and distress symptoms in adult CCS. METHODS: The SURfit trial randomized 151 CCS ≥16 years old, <16 at diagnosis and ≥5 years since diagnosis, identified through the Swiss Childhood Cancer Registry. Intervention participants received personalized PA counselling to increase intense PA by ≥2.5 h/week for 1 year. Controls maintained usual PA levels. The authors assessed physical- and mental-HRQOL, fatigue, and distress symptoms at baseline, 3, 6, and 12 months. T-scores were calculated using representative normative populations (mean = 50, standard deviation = 10). Generalized linear mixed-effects models with intention-to-treat (ITT, primary), and three per-protocol allocations were used. RESULTS: At 12 months, ITT (-3.56 larger decrease, 95% confidence interval -5.69 to -1.43, p = .001) and two per-protocol analyses found significantly lower fatigue. Physical-HRQOL improved significantly in two per-protocol analyses at 12 months. No other effects were found. CONCLUSION: SURfit showed that increased intense PA over 1 year improved fatigue in adult CCS. Survivors should be recommended PA to reduce the burden of late-effects.

Longitudinal changes of psychological distress among childhood cancer survivors: The Swiss Childhood Cancer Survivor Study.

BACKGROUND: Childhood cancer survivors may experience psychological distress due to the disease, cancer treatments, and potential late effects. Limited knowledge exists regarding longitudinal changes in psychological distress after childhood cancer. We aimed to determine changes in psychological distress over time and explore determinants of changes. METHODS: The Swiss Childhood Cancer Survivor Study collected data at baseline (2007-2009) and follow-up (2010-2012). Psychological distress was measured using the Brief Symptom Inventory 18 (BSI-18), including three symptom scales (somatization, depression, anxiety) and an overall distress index (Global Severity Index, GSI). Sum-scores were T-standardized (mean = 50; standard deviation [SD] = 10). Survivors with a score ≥57 on the GSI or two symptom scales were classified as cases with distress. We used linear mixed effects regression to identify potential sociodemographic and clinical determinants of change in psychological distress. RESULTS: We analyzed 696 survivors at baseline (mean age = 24 years [SD = 4], 49% females, mean time since diagnosis = 16 years [SD = 4]). On follow-up (2.4 years, SD = 1), 317 survivors were analyzed, including 302 participants with repeated measures. We found that 13% (39/302) were cases at baseline, and 25% (76/302) were cases on follow-up. Those older at study and longer since diagnosis, females, diagnosed with central nervous system (CNS) tumors, and those reporting late effects were more likely to experience higher levels of distress. Females and unemployed are at higher risk for developing or persisting psychological distress than males and those who are employed or in training. CONCLUSION: We observed an increase in psychological distress score over time, with higher proportion of psychological distress on follow-up. Anticipatory guidance and screening should be implemented in regular follow-up care.

Effect of a physical activity intervention on lower body bone health in childhood cancer survivors: A randomized controlled trial (SURfit).

It remains controversial whether physical activity promotes bone health in childhood cancer survivors (CCS). We aimed to assess the effect of a one-year general exercise intervention on lower body bone parameters of CCS. CCS ≥16 years at enrollment, <16 years at diagnosis and ≥5 years in remission were identified from the national Childhood Cancer Registry. Participants randomized to the intervention group were asked to perform an additional ≥2.5 hours of intense physical activity/week, controls continued exercise as usual. Bone health was assessed as a secondary trial endpoint at baseline and after 12-months. We measured tibia bone mineral density (BMD) and morphology by peripheral quantitative computed tomography and lumbar spine, hip and femoral neck BMD by dual-energy x-ray absorptiometry. We performed intention-to-treat, per protocol, and an explorative subgroup analyses looking at low BMD using multiple linear regressions. One hundred fifty-one survivors (44% females, 7.5 ± 4.9 years at diagnosis, 30.4 ± 8.6 years at baseline) were included. Intention-to-treat analysis revealed no differences in changes between the intervention and control group. Per protocol analyses showed evidence for an improvement in femoral neck and trabecular BMD between 1.5% and 1.8% more in participants being compliant with the exercise program. Trabecular BMD increased 2.8% more in survivors of the intervention group with BMD z-score ≤-1 compared to those starting at z-score >-1. A nonstandardized personalized exercise programs might not be specific enough to promote bone health in CCS, although those compliant and those most in need may benefit. Future trials should include bone stimulating exercise programs targeting risk groups with reduced bone health and motivational features to maximize compliance.

Effect of a 1-year physical activity intervention on cardiovascular health in long-term childhood cancer survivors-a randomised controlled trial (SURfit).

BACKGROUND: This randomised controlled trial (RCT) assessed the effect of a 1-year, partially supervised, physical activity (PA) intervention on a cardiovascular disease (CVD) risk score in adult survivors of childhood cancer. METHODS: We included childhood cancer survivors ≥16 y at enrolment, <16 y at diagnosis and ≥5 y in remission. The intervention group was asked to perform an additional ≥2.5 h of intense physical activity/week, controls continued exercise as usual; assessments were performed at baseline, 6 months (T6) and 12 months (T12). The primary endpoint was change in a CVD risk score (average z-score of waist circumference, blood pressure, fasting glucose, inverted high-density lipoprotein cholesterol, triglycerides, and inverted cardiorespiratory fitness) from baseline to T12. We performed intention-to-treat (ITT, primary) and 3 per protocol analyses. RESULTS: We randomised 151 survivors (44% females, 30.4 ± 8.6 years). We found a significant and robust reduction of the CVD risk score in the intervention compared to the control group at T6 and T12 across all analyses; with a difference in the reduction of the CVD risk z-score of -0.18 (95% confidence interval -0.29 to -0.06, P = 0.003) at T12 in favour of the intervention group (ITT analysis). CONCLUSIONS: This RCT showed that a long-term PA intervention can reduce CVD risk in long-term survivors of childhood cancer. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02730767.

Social, emotional, and behavioral functioning in young childhood cancer survivors with chronic health conditions.

BACKGROUND: The cancer diagnosis and its intensive treatment may affect the long-term psycho-social adjustment of childhood cancer survivors. We aimed to describe social, emotional, and behavioral functioning and their determinants in young childhood cancer survivors. PROCEDURE: The nationwide Swiss Childhood Cancer Survivor Study sends questionnaires to parents of survivors aged 5-15 years, who have survived at least 5 years after diagnosis. We assessed social, emotional, and behavioral functioning using the Strengths and Difficulties Questionnaire (SDQ). The SDQ includes four difficulties scales (emotional, conduct, hyperactivity, peer problems), a total difficulties indicator, and one strength scale (prosocial). We compared the proportion of survivors with borderline and abnormal scores to reference values and used multivariable logistic regression to identify determinants. RESULTS: Our study included 756 families (response rate of 72%). Thirteen percent of survivors had abnormal scores for the total difficulties indicator compared to 10% in the general population. The proportion of survivors with abnormal scores was highest for the emotional scale (15% vs. 8% in the general population), followed by the peer problems scale (14% vs. 7%), hyperactivity (8% vs. 10%), and conduct scale (6% vs. 7%). Few survivors (4% vs. 7%) had abnormal scores on the prosocial scale. Children with chronic health conditions had a higher risk of borderline and abnormal scores on all difficulties scales (all p < 0.05). CONCLUSION: Most childhood cancer survivors do well in social, emotional, and behavioral life domains, but children with chronic health conditions experience difficulties. Therefore, healthcare professionals should offer specific psycho-social support to these survivors.

Severity of hearing loss after platinum chemotherapy in childhood cancer survivors.

BACKGROUND: Hearing loss is a potential side effect from childhood cancer treatment. We described the severity of hearing loss assessed by audiometry in a representative national cohort of childhood cancer survivors (CCS) and identified clinical risk factors. PROCEDURE: We included all CCS from the Swiss Childhood Cancer Registry who were diagnosed ≤18 age and treated with platinum-based chemotherapy between 1990 and 2014. We extracted audiograms, treatment-related information, and demographic data from medical records. Two reviewers independently assessed the severity of hearing loss at latest follow-up using the Münster Ototoxicity Scale. We used ordered logistic regression to identify clinical risk factors for severity of hearing loss. RESULTS: We analyzed data from 270 CCS. Median time from cancer diagnosis to last audiogram was 5 years (interquartile range 2.5-8.1 years). We found 53 (20%) CCS with mild, 78 (29%) with moderate, and 75 (28%) with severe hearing loss. Higher severity grades were associated with (a) younger age at cancer diagnosis (odds ratio [OR] 5.4, 95% confidence interval [CI]: 2.5-12.0 for <5 years); (b) treatment in earlier years (OR 4.8, 95% CI: 2.1-11.0 for 1990-1995); (c) higher cumulative cisplatin doses (OR 13.5, 95% CI: 4.7-38.8 for >450 mg/m2 ); (d) concomitant cranial radiation therapy (CRT) (OR 4.4, 95% CI: 2.5-7.8); and (e) hematopoietic stem cell transplantation (HSCT) (OR 2.7, 95% CI: 1.0-7.2). CONCLUSION: Three of four CCS treated with platinum-based chemotherapy experienced some degree of hearing loss. We recommend closely monitoring patient's hearing function if treated at a young age with high cumulative cisplatin doses, and concomitant CRT as part of long-term care.

Mechanisms and functions of GABA co-release.

The 'one neuron, one neurotransmitter' doctrine states that synaptic communication between two neurons occurs through the release of a single chemical transmitter. However, recent findings suggest that neurons that communicate using more than one classical neurotransmitter are prevalent throughout the adult mammalian CNS. In particular, several populations of neurons previously thought to release only glutamate, acetylcholine, dopamine or histamine also release the major inhibitory neurotransmitter GABA. Here, we review these findings and discuss the implications of GABA co-release for synaptic transmission and plasticity.

Opposing force fields induce direction-specific sensorimotor adaptation but a non-specific perceptual shift consistent with a contraction of peripersonal space representation.

Most of our daily interactions with objects occur in the space immediately surrounding the body, i.e. the peripersonal space. The peripersonal space is characterized by multisensory processing of objects which are coded in terms of potential actions, specifying for instance whether objects are within reach or not. Our recent work suggested a link between exposure to a new force field, which changed the effector dynamics, and the representation of peripersonal space. To better understand the interplay between the plasticity of the motor system and peripersonal space representation, the present study examined whether changing the direction of the force field specifically modified the perception of action boundaries. Participants seated at the centre of an experimental platform estimated visual targets' reachability before and after adapting upper-limb reaching movements to the Coriolis force generated by either clockwise or counter clockwise rotation of the platform (120°/s). Opposite spatial after-effects were observed, showing that force-field adaptation depends on the direction of the rotation. In contrast, perceived action boundaries shifted leftward following exposure to the new force field, regardless of the direction of the rotation. Overall, these findings support the idea that abrupt exposure to a new force field results in a direction-specific updating of the central sensorimotor representations underlying the control of arm movements. Abrupt exposure to a new force field also results in a nonspecific shift in the perception of action boundaries, which is consistent with a contraction of the peripersonal space. Such effect, which does not appear to be related to state anxiety, could be related to the protective role of the peripersonal space in response to the uncertainty of the sensorimotor system induced by the abrupt modification of the environment.

High impact physical activity and bone health of lower extremities in childhood cancer survivors: A cross-sectional study of SURfit.

Childhood cancer survivors (CCS) are at risk of reduced bone health and premature osteoporosis. As physical activity with high impact loading (IL-PA) is known to promote bone health, we compared bone densitometry and microstructure between groups of CCS who performed different amounts of physical activities in their daily life. We used baseline data of a single-center PA trial including 161 CCS from the Swiss Childhood Cancer Registry, aged <16 at diagnosis, ≥16 at study and ≥5 years since diagnosis. Lower body bone health was assessed with peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA). Daily IL-PA (duration in activities >2 g acceleration and numbers of vertical impacts/hr >2 g) was captured using hip-worn accelerometers (1-3 weeks). For both IL-PA approaches, we formed low, middle and high activity groups based on tertiles. Bone health of the high and middle active groups was compared to the low active group. 63% of CCS had indication of at least one bone mineral density z-score ≤ -1 measured by pQCT or DXA. The high IL-PA group performing 2.8 min/day or 19.1 impact peaks/hr > 2 g (median) showed about 3-13% better microstructural and densitometric bone health as compared to the low IL-PA group with 0.38 min/day or 0.85 peaks/hr > 2 g. Just a few minutes and repetitions of high IL-PA as easily modifiable lifestyle factor may be sufficient to improve bone health in adult CCS. Future longitudinal research is needed to better understand pattern and dosage of minimal impact loading needed to strengthen bone in growing and adult CCS.

No evidence of overweight in long-term survivors of childhood cancer after glucocorticoid treatment.

BACKGROUND: Glucocorticoids can lead to weight gain during cancer treatment, but to the authors' knowledge, little is known regarding their long-term effects in childhood cancer survivors (CCS). METHODS: As part of the Swiss Childhood Cancer Survivor Study, the authors sent a questionnaire to CCS aged <21 years at diagnosis who were residing in Switzerland, had survived ≥5 years, and were aged 15 to 45 years at the time of the survey. Cumulative doses of glucocorticoids were assessed from medical records and study protocols and body mass index was calculated from self-reported height and weight at the time of the survey. The authors compared the prevalence of overweight between CCS, their siblings, and the general population (Swiss Health Survey [SHS]) and investigated the association between overweight and treatment-related risk factors using multivariable logistic regression. RESULTS: The study included 1936 CCS, 546 siblings, and 9591 SHS participants. The median age of the CCS at the time of the survey was 24 years (interquartile range, 20-31 years) and the median time since diagnosis was 17 years (interquartile range, 12-22 years). At the time of the survey, approximately 26% of CCS were overweight, a percentage that was comparable to that among siblings (24%) and the SHS participants (25%). The prevalence of overweight was 24% in CCS treated with glucocorticoids only (686 CCS), 37% in those treated with cranial radiotherapy (CRT) (127 CCS), and 49% in those who received treatment with both glucocorticoids and CRT (101 CCS) (P < .001). The authors found no evidence of a dose-response relationship between cumulative glucocorticoid doses and overweight and no evidence that CRT modified the effect of the cumulative glucocorticoid dose on overweight. CONCLUSIONS: The results of the current study suggest that glucocorticoids used for the treatment of childhood cancer are not associated with long-term risk of overweight.

Long-term pulmonary disease among Swiss childhood cancer survivors.

BACKGROUND: Pulmonary diseases are potentially severe late complications of childhood cancer treatment that increase mortality risk among survivors. This nationwide study assesses the prevalence and incidence of pulmonary diseases in long-term childhood cancer survivors (CCS) and their siblings, and quantifies treatment-related risks. METHODS: As part of the Swiss Childhood Cancer Survivor Study, we studied CCS who were diagnosed between 1976 and 2005 and alive at least 5 years after diagnosis. We compared prevalence of self-reported pulmonary diseases (pneumonia, chest wall abnormalities, lung fibrosis, emphysema) between CCS and their siblings, calculated cumulative incidence of pulmonary diseases using the Kaplan-Meier method, and determined risk factors using multivariable logistic regression. RESULTS: CCS reported more pneumonias (10% vs. 7%, P = 0.020) and chest wall abnormalities (2% vs. 0.4%, P = 0.003) than siblings. Treatment with busulfan was associated with prevalence of pneumonia (odds ratio [OR] 4.0, 95% confidence interval [CI] 1.1-14.9), and thoracic surgery was associated with chest wall abnormalities and lung fibrosis (OR 4.1, 95% CI 1.6-10.7 and OR 6.3, 95% CI 1.7-26.6). Cumulative incidence of any pulmonary disease after 35 years of follow-up was 21%. For pneumonia, the highest cumulative incidence was seen in CCS treated with both pulmotoxic chemotherapy and radiotherapy to the thorax (23%). CONCLUSION: This nationwide study in CCS found an increased risk for pulmonary diseases, especially pneumonia, while still young, which indicates that CCS need long-term pulmonary follow-up.

Monitoring pulmonary health in Swiss childhood cancer survivors.

BACKGROUND: Childhood cancer survivors are at increased risk for pulmonary morbidity and mortality. International guidelines recommend pulmonary function tests (PFT) during follow-up care. This nationwide study assessed how many children received PFT within 5 years after pulmotoxic treatment in Switzerland, types of tests, and predictors for testing. METHODS: We included all children from the Swiss Childhood Cancer Registry who were diagnosed with cancer from 1990 to 2013 at age 0-16 years, survived for ≥2 years from diagnosis, and had pulmotoxic chemotherapy with bleomycin, busulfan, nitrosoureas, and/or chest radiotherapy. We searched medical records in all Swiss pediatric oncology clinics for PFT (spirometry, plethysmography, diffusion capacity of carbon monoxide [DLCO]) and treatment details. RESULTS: We found medical records for 372 children, of whom 147 had pulmotoxic chemotherapy and 323 chest radiotherapy. Only 185 had plethysmography and/or spirometry (50%), 122 had DLCO (33%). Testing varied by cancer center from 3% to 79% (P = 0.001). Central nervous system tumor survivors and those not treated according to study protocols had less plethysmography and/or spirometry (odds ratio (OR) 0.3 and 0.3), lymphoma survivors and those who were symptomatic had more PFT (plethysmography and/or spirometry: OR 5.9 and 8.7; DLCO: OR 3.4 and 2.3). Cumulative incidence (CuI) of PFT was 52% in the first 5 years after pulmotoxic treatment; most of the tests were done in the first 2 years after treatment (CuI 44%). CONCLUSION: Only half of the survivors exposed to pulmotoxic treatment have been followed up with PFT in Switzerland. We need to optimize, update, and implement monitoring guidelines.

Dopaminergic neurons inhibit striatal output through non-canonical release of GABA.

The substantia nigra pars compacta and ventral tegmental area contain the two largest populations of dopamine-releasing neurons in the mammalian brain. These neurons extend elaborate projections in the striatum, a large subcortical structure implicated in motor planning and reward-based learning. Phasic activation of dopaminergic neurons in response to salient or reward-predicting stimuli is thought to modulate striatal output through the release of dopamine to promote and reinforce motor action. Here we show that activation of dopamine neurons in striatal slices rapidly inhibits action potential firing in both direct- and indirect-pathway striatal projection neurons through vesicular release of the inhibitory transmitter GABA (γ-aminobutyric acid). GABA is released directly from dopaminergic axons but in a manner that is independent of the vesicular GABA transporter VGAT. Instead, GABA release requires activity of the vesicular monoamine transporter VMAT2, which is the vesicular transporter for dopamine. Furthermore, VMAT2 expression in GABAergic neurons lacking VGAT is sufficient to sustain GABA release. Thus, these findings expand the repertoire of synaptic mechanisms used by dopamine neurons to influence basal ganglia circuits, show a new substrate whose transport is dependent on VMAT2 and demonstrate that GABA can function as a bona fide co-transmitter in monoaminergic neurons.

Childhood cancer survival in Switzerland (1976-2013): Time-trends and predictors.

Population-based studies on childhood cancer survival are key to monitor progress against cancer and to detect potential differences between regions and other subgroups in the population. We investigated time trends and factors associated with childhood cancer survival on a national level in Switzerland, from 1976 to 2013. We extracted data from the population-based Swiss Childhood Cancer Registry of 5,776 children (age 0-14 years) diagnosed with cancer from 1985 to 2014 in Switzerland. We calculated age-adjusted 5-year survival, defined the annual reduction in risk of death (ARR), and explored associations of survival with clinical and demographic factors. Overall, 5-year survival improved significantly, from 64% in 1976-1983 to 88% in 2004-2013. ARR over the whole period was 4% for all diagnostic groups, greatest for Hodgkin lymphomas (8%), ependymomas (6%), Burkitt's lymphomas (6%) and germ cell tumours (6%). Children treated in hospitals without specialised paediatric cancer centre for leukaemia (HR 12.9), lymphoma (HR 5.0) and neuroblastoma (HR 3.7) were at higher risk of death. In French-speaking Switzerland, risk of death was lower for lymphoma (HR 0.6), CNS tumours (HR 0.7) and neuroblastoma (HR 0.5). Children with migration background had a higher risk of death from all tumours except bone tumours. Childhood cancer survival significantly improved from 1976 to 2013, but there is room for further improvement. Survival rates varied by type of clinical treatment, language region and nationality. All paediatric cancer patients should be referred to a specialised paediatric cancer centre. Further research is needed to intervene and completely eliminate inequalities in survival.

A partially supervised physical activity program for adult and adolescent survivors of childhood cancer (SURfit): study design of a randomized controlled trial [NCT02730767].

BACKGROUND: Beyond survival of nowadays >80%, modern childhood cancer treatment strives to preserve long-term health and quality of life. However, the majority of today's survivors suffer from short- and long-term adverse effects such as cardiovascular and pulmonary diseases, obesity, osteoporosis, fatigue, depression, and reduced physical fitness and quality of life. Regular exercise can play a major role to mitigate or prevent such late-effects. Despite this, there are no data on the effects of regular exercise in childhood cancer survivors from randomized controlled trials (RCTs). Primary outcome of the current RCT is therefore the effect of a 12-months exercise program on a composite cardiovascular disease risk score in childhood cancer survivors. Secondary outcomes are single cardiovascular disease risk factors, glycaemic control, bone health, body composition, physical fitness, physical activity, quality of life, mental health, fatigue and adverse events (safety). METHODS: A total of 150 childhood cancer survivors aged ≥16 years and diagnosed ≥5 years prior to the study are recruited from Swiss paediatric oncology clinics. Following the baseline assessments patients are randomized 1:1 into an intervention and control group. Thereafter, they are seen at month 3, 6 and 12 for follow-up assessments. The intervention group is asked to add ≥2.5 h of intense physical activity/week, including 30 min of strength building and 2 h of aerobic exercises. In addition, they are told to reduce screen time by 25%. Regular consulting by physiotherapists, individual web-based activity diaries, and pedometer devices are used as motivational tools for the intervention group. The control group is asked to keep their physical activity levels constant. DISCUSSION: The results of this study will show whether a partially supervised exercise intervention can improve cardiovascular disease risk factors, bone health, body composition, physical activity and fitness, fatigue, mental health and quality of life in childhood cancer survivors. If the program will be effective, all relevant information of the SURfit physical activity intervention will be made available to interested clinics that treat and follow-up childhood cancer patients to promote exercise in their patients. TRIAL REGISTRATION: Prospectively registered in clinicaltrials.gov [ NCT02730767 ], registration date: 10.12.2015.

Socioeconomic disparities in childhood cancer survival in Switzerland.

In this study, we investigated whether childhood cancer survival in Switzerland is influenced by socioeconomic status (SES), and if disparities vary by type of cancer and definition of SES (parental education, living condition, area-based SES). Using Cox proportional hazards models, we analyzed 5-year cumulative mortality in all patients registered in the Swiss Childhood Cancer Registry diagnosed 1991-2006 below 16 years. Information on SES was extracted from the Swiss census by probabilistic record linkage. The study included 1602 children (33% with leukemia, 20% with lymphoma, 22% with central nervous system (CNS) tumors); with an overall 5-year survival of 77% (95%CI 75-79%). Higher SES, particularly parents' education, was associated with a lower 5-year cumulative mortality. Results varied by type of cancer with no association for leukemia and particularly strong effects for CNS tumor patients, where mortality hazard ratios for the different SES indicators, comparing the highest with the lowest group, ranged from 0.48 (95%CI: 0.28-0.81) to 0.71 (95%CI: 0.44-1.15). We conclude that even in Switzerland with a high quality health care system and mandatory health insurance, socioeconomic differences in childhood cancer survival persist. Factors causing these survival differences have to be further explored, to facilitate universal access to optimal treatment and finally eliminate social inequalities in childhood cancer survival.

Multiphasic modulation of cholinergic interneurons by nigrostriatal afferents.

The motor and learning functions of the striatum are critically dependent on synaptic transmission from midbrain dopamine neurons and striatal cholinergic interneurons (CINs). Both neural populations alter their discharge in vivo in response to salient sensory stimuli, albeit in opposite directions. Whereas midbrain dopamine neurons respond to salient stimuli with a brief burst of activity, CINs exhibit a distinct pause in firing that is often followed by a period of increased excitability. Although this "pause-rebound" sensory response requires dopaminergic signaling, the precise mechanisms underlying the modulation of CIN firing by dopaminergic afferents remain unclear. Here, we show that phasic activation of nigrostriatal afferents in a mouse striatal slice preparation is sufficient to evoke a pause-rebound response in CINs. Using a combination of optogenetic, electrophysiological, and pharmacological approaches, we demonstrate that synaptically released dopamine inhibits CINs through type 2 dopamine receptors, while another unidentified transmitter mediates the delayed excitation. These findings imply that, in addition to their direct effects on striatal projection neurons, midbrain dopamine neurons indirectly modulate striatal output by dynamically controlling cholinergic tone. In addition, our data suggest that phasic dopaminergic activity may directly participate in the characteristic pause-rebound sensory response that CINs exhibit in vivo in response to salient and conditioned stimuli.

Symmetry recovery for coupled photonic modes with transversal PT symmetry.

Typical parity-time (PT) symmetric structures switch from the unbroken to the broken phase when gain increases through an exceptional point. In contrast, we report on systems with the unusual, reverse behavior, where the symmetric phase is recovered after a broken phase. We study this phenomenon analytically and numerically in the simplest possible system, consisting of four coupled modes, and we present potential dielectric and plasmonic implementations. The complex mode merging scheme, with two distinct unbroken PT phases encompassing a broken one, appears for a specific proportion range of the coupling constants. This regime with "inverse" exceptional points is interesting for the design of novel PT devices.